I agree with the others- take the year or more off! After 4 months at home with my second baby, I went back to work part-time (I'm also a school teacher). We hired the MOST amazing nanny ever from January through the end of the school year. While she was incredible- perfect with the kids, doing everything and more than we hoped for, it still wasn't ME. I'll never forget the day it snowed, but not enough to say home from work. All I could think about was how my nanny was getting to share this brand new event with my Anna instead of me.
I took the next year off, and now am in my second year off. I miss teaching an awful lot, but I am very happy with my choice. My colleagues continue to be really supportive when I go back to visit; every single person who is older than me says some variation of, "J., you're making the right choice. You can't ever get those years back." The people who did something similar with their careers swear by it, and the ones who did NOT are very very regretful.
Just keep in touch with your colleagues, attend seminars/workshops now and then so you stay up to date, and especially keep those ties with any administrators you're tight with.
And, don't forget: you can always change your mind! Let's say you decide to take next year off, and then come January you're losing your mind and think it was the worst decision of your life? There is ALWAYS a job out there- whether it's subbing, doing someone else's maternity leave, etc. Your choice for next year doesn't have to be etched in stone. When my mom gave me this same advice, I breathed a huge sigh of relief and allowed myself to let go of my worries over making the "right" choice. I hope it works for you, too.
Good luck!
J.